Issue and/or context: As tracked on issue #2407 / [sc-51048].

Changes:

Extracting readback of core domain, current domain, and non-empty domain are all currently:

• Done slotwise within libtiledbsoma, templatized;
• For Python: there is a loop over dim names in the pybind11 layer lke this

  TileDB-SOMA/apis/python/src/tiledbsoma/soma_array.cc

  Lines 671 to 830 in b3feada

  	.def(
  	"non_empty_domain",
  	[](SOMAArray& array, std::string name, py::dtype dtype) {
  	switch (np_to_tdb_dtype(dtype)) {
  	case TILEDB_UINT64:
  	return py::cast(
  	array.non_empty_domain_slot<uint64_t>(name));
  	case TILEDB_DATETIME_YEAR:
  	case TILEDB_DATETIME_MONTH:
  	case TILEDB_DATETIME_WEEK:
  	case TILEDB_DATETIME_DAY:
  	case TILEDB_DATETIME_HR:
  	case TILEDB_DATETIME_MIN:
  	case TILEDB_DATETIME_SEC:
  	case TILEDB_DATETIME_MS:
  	case TILEDB_DATETIME_US:
  	case TILEDB_DATETIME_NS:
  	case TILEDB_DATETIME_PS:
  	case TILEDB_DATETIME_FS:
  	case TILEDB_DATETIME_AS:
  	case TILEDB_INT64:
  	return py::cast(
  	array.non_empty_domain_slot<int64_t>(name));
  	case TILEDB_UINT32:
  	return py::cast(
  	array.non_empty_domain_slot<uint32_t>(name));
  	case TILEDB_INT32:
  	return py::cast(
  	array.non_empty_domain_slot<int32_t>(name));
  	case TILEDB_UINT16:
  	return py::cast(
  	array.non_empty_domain_slot<uint16_t>(name));
  	case TILEDB_INT16:
  	return py::cast(
  	array.non_empty_domain_slot<int16_t>(name));
  	case TILEDB_UINT8:
  	return py::cast(
  	array.non_empty_domain_slot<uint8_t>(name));
  	case TILEDB_INT8:
  	return py::cast(
  	array.non_empty_domain_slot<int8_t>(name));
  	case TILEDB_FLOAT64:
  	return py::cast(
  	array.non_empty_domain_slot<double>(name));
  	case TILEDB_FLOAT32:
  	return py::cast(
  	array.non_empty_domain_slot<float>(name));
  	case TILEDB_STRING_UTF8:
  	case TILEDB_STRING_ASCII:
  	return py::cast(array.non_empty_domain_slot_var(name));
  	default:
  	throw TileDBSOMAError(
  	"Unsupported dtype for nonempty domain.");
  	}
  	})
  	.def(
  	"soma_domain_slot",
  	[](SOMAArray& array, std::string name, py::dtype dtype) {
  	switch (np_to_tdb_dtype(dtype)) {
  	case TILEDB_UINT64:
  	return py::cast(array.soma_domain_slot<uint64_t>(name));
  	case TILEDB_DATETIME_YEAR:
  	case TILEDB_DATETIME_MONTH:
  	case TILEDB_DATETIME_WEEK:
  	case TILEDB_DATETIME_DAY:
  	case TILEDB_DATETIME_HR:
  	case TILEDB_DATETIME_MIN:
  	case TILEDB_DATETIME_SEC:
  	case TILEDB_DATETIME_MS:
  	case TILEDB_DATETIME_US:
  	case TILEDB_DATETIME_NS:
  	case TILEDB_DATETIME_PS:
  	case TILEDB_DATETIME_FS:
  	case TILEDB_DATETIME_AS:
  	case TILEDB_INT64:
  	return py::cast(array.soma_domain_slot<int64_t>(name));
  	case TILEDB_UINT32:
  	return py::cast(array.soma_domain_slot<uint32_t>(name));
  	case TILEDB_INT32:
  	return py::cast(array.soma_domain_slot<int32_t>(name));
  	case TILEDB_UINT16:
  	return py::cast(array.soma_domain_slot<uint16_t>(name));
  	case TILEDB_INT16:
  	return py::cast(array.soma_domain_slot<int16_t>(name));
  	case TILEDB_UINT8:
  	return py::cast(array.soma_domain_slot<uint8_t>(name));
  	case TILEDB_INT8:
  	return py::cast(array.soma_domain_slot<int8_t>(name));
  	case TILEDB_FLOAT64:
  	return py::cast(array.soma_domain_slot<double>(name));
  	case TILEDB_FLOAT32:
  	return py::cast(array.soma_domain_slot<float>(name));
  	case TILEDB_STRING_UTF8:
  	case TILEDB_STRING_ASCII: {
  	std::pair<std::string, std::string> str_domain;
  	return py::cast(std::make_pair("", ""));
  	}
  	default:
  	throw TileDBSOMAError(
  	"Unsupported dtype for Dimension's domain");
  	}
  	})
  	.def(
  	"soma_maxdomain_slot",
  	[](SOMAArray& array, std::string name, py::dtype dtype) {
  	switch (np_to_tdb_dtype(dtype)) {
  	case TILEDB_UINT64:
  	return py::cast(
  	array.soma_maxdomain_slot<uint64_t>(name));
  	case TILEDB_DATETIME_YEAR:
  	case TILEDB_DATETIME_MONTH:
  	case TILEDB_DATETIME_WEEK:
  	case TILEDB_DATETIME_DAY:
  	case TILEDB_DATETIME_HR:
  	case TILEDB_DATETIME_MIN:
  	case TILEDB_DATETIME_SEC:
  	case TILEDB_DATETIME_MS:
  	case TILEDB_DATETIME_US:
  	case TILEDB_DATETIME_NS:
  	case TILEDB_DATETIME_PS:
  	case TILEDB_DATETIME_FS:
  	case TILEDB_DATETIME_AS:
  	case TILEDB_INT64:
  	return py::cast(
  	array.soma_maxdomain_slot<int64_t>(name));
  	case TILEDB_UINT32:
  	return py::cast(
  	array.soma_maxdomain_slot<uint32_t>(name));
  	case TILEDB_INT32:
  	return py::cast(
  	array.soma_maxdomain_slot<int32_t>(name));
  	case TILEDB_UINT16:
  	return py::cast(
  	array.soma_maxdomain_slot<uint16_t>(name));
  	case TILEDB_INT16:
  	return py::cast(
  	array.soma_maxdomain_slot<int16_t>(name));
  	case TILEDB_UINT8:
  	return py::cast(
  	array.soma_maxdomain_slot<uint8_t>(name));
  	case TILEDB_INT8:
  	return py::cast(
  	array.soma_maxdomain_slot<int8_t>(name));
  	case TILEDB_FLOAT64:
  	return py::cast(
  	array.soma_maxdomain_slot<double>(name));
  	case TILEDB_FLOAT32:
  	return py::cast(array.soma_maxdomain_slot<float>(name));
  	case TILEDB_STRING_UTF8:
  	case TILEDB_STRING_ASCII: {
  	std::pair<std::string, std::string> str_domain;
  	return py::cast(std::make_pair("", ""));
  	}
  	default:
  	throw TileDBSOMAError(
  	"Unsupported dtype for Dimension's domain");
  	}
  	})

  ;
• For R: currently these are using TileDB-R -- which is a dependency we're currently removing -- and I don't want to imitate the above in R

The best option for Python/R interop is:

• Push down loop-over-dim-names to libtiledbsoma
• Make more use of nanoarrow to interface with Python and R

The current PR simply moves some code currently used in libtiledbsoma's unit-test logic to ArrowAdapter, where it can -- and will -- be used for readback of core domain, current domain, and non-empty domain for #2407.

Notes for Reviewer:

This is just a code-move. If all existing unit tests pass, that is success. No new unit tests are introduced here, since no new unit tests are needed.